In Upper East and West Tennessee, GOP incumbents barely scraped past voters, with five votes in one case and 11 in another.

Travis won the bitterly fought GOP primary with 50.6 percent of the vote, a 105-vote margin. The district comprises all of Rhea, Sequatchie and Bledsoe counties and a portion of Roane County.

Travis has no Democratic opponent in the Nov. 6 general election,

Figures also show four House Democratic incumbents lost in contested primaries. Three faced fellow incumbent Democrats as a result of Republican-controlled redistricting. Republicans squeezed six Democrats into three districts, and all six chose to run.

One such contest was the 28th District in Chattanooga. Rep. Tommie Brown lost to Rep. JoAnne Favors by a 3-to-1 margin after much of Favors' district was merged into District 28. Four incumbents also fought it out in two Memphis districts.

In the fourth loss, the Nashville incumbent was unseated by a challenger.

Many races were decided on razor-thin margins, including the GOP contest for the 10th Senate District in parts of Hamilton and Bradley counties.

The Tennessee Secretary of State's website shows Todd Gardenhire with 50.1 percent of the vote over Greg Vital. Just 40 votes separate them, and provisional ballots will be counted Monday.

Vital's campaign spokesman said Saturday the campaign will decide this week whether to seek a recount.

During the House District 31 contest, Cobb questioned Travis' credentials as a Republican, saying Travis had voted in at least two Democratic primaries in recent years.

Republican election officials in Rhea County, meanwhile, challenged at least 10 primary voters on grounds they had voted in Democratic primaries or had mixed records.

Cobb said he wasn't behind the challenges to voters, noting a number of them would be supporting him.

He could not be reached Friday on whether he might ask for a recount or otherwise challenge the election's outcome.

Travis said Friday afternoon he was not aware of any potential challenge Cobb might make.

"He called and congratulated me this morning," Travis said.

INFIGHTING

With a 64-34 majority, Republicans firmly controlled the House heading into the 2012 election cycle. There is one independent in the 99-member chamber.

Yet opponents came rushing into GOP primaries in Republican districts made increasingly safe through GOP redistricting.

In some cases, tea party insurgents, gun-rights groups and others played key roles in toppling incumbents.

In the best-known case, House Republican Caucus Chairman Debra Maggart, R-Hendersonville, fell to GOP challenger Courtney Rogers. The National Rifle Association, Tennessee Firearms Association and other groups jumped in with independent expenditures to back Rogers.